If you care about a clean kill at 100 ft., the Red Ryder won't cut it. For a squirrel, I wouldn't use it at any distance. Small rats - maybe close up.

Beeman has a few low end, Chinese models - the RS1 ain't bad. It's accurate enough, and more importantly has the power to kill a rat/squirrel at the distance you are looking for.

Usually, it's around $100 - just found it for less here.

Don't know anything about the dealer above...I've seen the RS1 at local sporting goods dealers as well.